A Validated Stability Indicating RP-HPLC Method Development and Validation for Simultaneous Estimation of Aliskiren Hemifumarate and Amlodipine Besylate in Pharmaceutical Dosage Form

The present study describes the stability indicating RP-HPLC method for simultaneous estimation of aliskiren hemifumarate and amlodipine besylate in pharmaceutical dosage forms. The proposed RP-HPLC method was developed by using waters 2695 separation module equipped with PDA detector and chromatographic separation was carried on C-8 Inertsil ODS (150 × 4.6 mm, 5 µ) column at a flow rate of 1 mL/min and the run time is 10 min. The mobile phase consisted of phosphate buffer and acetonitrile in the ratio of 40 : 60% v/v and pH was adjusted to 3 with orthophosphoric acid and eluents were scanned using PDA detector at 237 nm. The retention time of aliskiren and amlodipine was found to be 3.98 and 5.14 min, respectively. A linearity response was observed in the concentration range of 30–225 µg/mL for aliskiren and 2–15 µg/mL for amlodipine, respectively. Limit of detection and limit of quantification for aliskiren are 0.161 µg/mL and 0.489 µg/mL and for amlodipine are 0.133 µg/mL and 0.404 µg/mL, respectively. The stability indicating method was developed by subjecting the drugs to stress conditions such as acid and base hydrolysis, oxidation, and photo- and thermal degradation and the degraded products formed were resolved successfully from the samples.